RTI_TRANSACTION subroutine
Description
RTI_TRANSACTION enables transaction processing (commit and rollback) for those filing systems that support it. The program calls the native transaction mechanisms of the filing system. For example, if RTI_TRANSACTION is used against a TigerLogic D3 volume, then it will use D3’s transaction commit and rollback. RTI_Transaction supports Linear Hash (RTP57, “traditional” OpenInsight table) , other multivalue (MVBFS), and SQL (DSBFS) volumes.
Syntax
status = RTI_TRANSACTION(volname, method, errStatus)
Parameters
The function has the following parameters:
| Parameter | Description | |
|---|---|---|
| Volname (in) | name/path of the volume or connection. The volume must be attached prior to calling RTI_TRANSACTION. For linear hash filing systems, this may be null (“”). | |
| method (in) | “BEGIN” to begin a transaction “COMMIT” to commit changes “ ROLLBACK” to rollback changes to the starting point | |
| errStatus (out) | error or status information passed back from the filing system | |
Returns
True (1) on success
False (0) on failure. If failed, see ErrStatus for details
Notes
RTI_TRANSACTION supports the MVBFS, DSBFS and RTP57 filing systems. It returns an error if used with a volume bound to any other filing system. RTI_TRANSACTION operates on a per volume basis. If you need to commit and rollback across volumes you should call the function for each volume. RTI_Transaction passes its calls to the native filing system. For a linear hash volume, RTI_TRANSACTION is identical to using the TRANSACT subroutine. You are responsible for configuring the underlying server to support transactions.
Examples
MVBFS
errStatus =''
* Begin the transaction
* volname is the name you used in the connection / attach
* call attach_Table(“MVBFS_TEST”, ‘’, ‘’)
stat = rti_transaction(volname, 'BEGIN', errStatus)
* Read a record in a reversable manner
If stat then
stat = RTI_READU( f_customers, cust_id, cust_rec)
End
* Change it, write it back
If stat Then
cust_rec<1> = ' changed ' : timedate()
stat = RTI_WRITEU( f_customers, cust_id, cust_rec)
End
stat = RTI_READU( f_orders, order_id, orders_rec)
If stat Then
orders_Rec<1> = ' changed ' : timedate()
stat = RTI_WRITEU( f_orders, order_id, orders_rec)
End
* Success? else roll back
If stat then
stat = rti_transaction(volname, 'COMMIT', errStatus)
End Else
stat = rti_transaction(volname, 'ROLLBACK', errStatus)
End
SQL
* Begin the transaction
stat = rti_transaction(volname, 'BEGIN', errStatus)
If stat then
Read cust_rec from f_customers, cust_id Else
stat = false$
end
End
* Change it, write it back
If stat Then
cust_rec<1> = ' changed ' : timedate()
Write cust_rec On f_customers, cust_id Else
stat = false$
end
End
If stat then
Read orders_rec from f_orders, order_id Else
stat = false$
end
End
* Change it, write it back
If stat Then
orders_rec<1> = ' changed ' : timedate()
Write orders_rec On f_orders, order_id Else
stat = false$
end
End
* Success? else roll back
If stat then
stat = rti_transaction(volname, 'COMMIT', errStatus)
End Else
stat = rti_transaction(volname, 'ROLLBACK', errStatus)
End
Linear hash
errStatus = ''
* VOLNAME not required for linear hash use – pass “” instead
* Begin the transaction
stat = rti_transaction('', 'BEGIN', errStatus)
* Read a record in a reversable manner
If stat then
Lock f_customers, cust_id then
Read cust_rec from f_customers, cust_id Else
stat = false$
end
* Change it, write it back
If stat Then
cust_rec<1> = ' changed ' : timedate()
Write cust_rec On f_customers, cust_id Else
stat = false$
end
End
UnLock f_customers, cust_id Else null
End Else
stat = false$
End
end
If stat Then
Lock f_customers, cust_id then
Read orders_rec from f_orders, order_id Else
stat = false$
end
* Change it, write it back
If stat Then
orders_rec<1> = ' changed ' : timedate()
Write orders_rec On f_orders, order_id Else
stat = false$
end
End
UnLock f_orders, order_id Else null
End Else
stat = false$
End
end
* Success? else roll back
If stat then
stat = rti_transaction('', 'COMMIT', errStatus)
End Else
stat = rti_transaction('', 'ROLLBACK', errStatus)
End